Last Updated 06/09/00
Caterham Leather Adjustable Seat Repair
I have leather S type seats in my Caterham which are very light and I find then extremely comfortable. However, they are a bit fragile with some early models often cracking a weld and all of them are susceptible to the plastic rear panel splitting. This happened to me so I took it to pieces, got a mould made of the old seat back and from it a new fibreglass seatback that it much stronger. Carbon fibre or kevlar could have easily been used. An explanation of this and pictures follow. I have a mould which I will lend to people wishing to do this for a donation to the List (and Lotus 7 club of GB) charity: Neuk the Leuk or NtL a leukaemia research fund.
The bottom of the leather is wrapped around the bottom seat rail and then the attracted plastic is glued to the seat back. The plastic that extends past the leather will later be removed so some violence with a Stanley knife can be used to cut this out. The excess plastic can then be trimmed as in the second picture. Don't worry if the plastic splits a bit. The top is easily removed as a plastic strip on the leather tucks into a slot in the seat back and is easily pulled out.
1) Cut out the glued join at the bottom
2) Trim it
The leather seat cover is glued to the seat backing and tie wrapped to both the backing and the frame. The tie wraps should be cut and the leather pulled off the backing. The glue will remove some of the foam but not too much. There are also large foam pads for the lumbar and upper back regions of the seat. Once this is done the old back can be removed (keep it for the moment) to reveal the seat frame - check the welds on this.
3) The old seat back
4) The seat frame
5) The new seat back from the rear
6) And from the front
The new seat back does not have any holes in it for tie wraps. The correct positions can be located by looking for the slight marks in it and by comparing with the old seat back.
7) Drill here to make a tie wrap hole
The seat back can no be positioned on the frame, this requires a bit of fiddling to get it to sit correctly but once in place it is quite firm.
8) Seat back location at the bottom...
9) ...The side...
10) ...And the top
The foam lumbar pad can now be glued onto the seat back. The upper foam pad is a little harder as it has to go around the top and cover the upper region of the seat. It may be necessary to get a second pair of hands to help hold this whilst the glue sets. Take care to ensure that the hole for the headrest is clear.
11) Lumbar pad
12) Upper pad
The leather cover can now be placed over the seat and tie wrapped into place. Cover the foam on the plastic seat back with glue beforehand. When placing it over be careful to ensure that the spring mechanism that holds the headrest firm is in place. It should have a bit of bent coathanger holding a 3 inch plastic coated metal pin in place. Tie wraps can then be passed through the seat back, around the seat frame and through the holes in the sides of the seat cover. This is 6 tie wraps in total, 3 on each side. Don't tighten the top pair yet.
13) Place the seat cover over the frame
14) Thread a tie wrap through the seatback and leather at the bottom...
15) ...and around the frame...
16) ...and tighten
17) Do the same half way up the seat as well...
18) ...and tighten
The plastic edged leather can now be tucked under the bottom rail of the frame.
19) Tuck in the bottom
20) And a close-up
Now for the top. The idea is to create something similar to the bottom of the seat but as there is no rail here you need to make one. I used a strip 1mm of aluminium about 4 inches longer than the width of the seat and 1cm wide. Put this between the seat frame and the seat back, then bend it around the rail and crimp it down as in picture 21. The leather can then be tucked in.
21) The top aluminium bracket
22) With the leather tucked into it
Provided you used enough glue (I didn't use any the first time so it looks rubbish in this picture so I had to redo it) the seat should now look as it used to from the front and from behind only the lack of a crack and glimpse of aluminium hint at the new backing :)
23) All done